Question

I have a class and it has a couple data structures in it among which is a hashmap. But I want the hashmap to have default values so I need to preload it. How do I do this since I can’t use put method inside the object?

class Profile
{
    HashMap closedAges = new HashMap();
    closedAges.put("19");
}

I fixed it with this but I had to use a method within the object.

class Profile
{   
    HashMap closedAges = loadAges();
    HashMap loadAges()
    {
        HashMap closedAges = new HashMap();

        String[] ages = {"19", "46", "54", "56", "83"};
        for (String age : ages)
        {
            closedAges.put(age, false);
        }
        return closedAges;
    }
}

Answer 1

You could do this:

Map<String, String> map = new HashMap<String, String>() {{
   put("1", "one");
   put("2", "two");
   put("3", "three");
}};

This java idiom is called double brace initialization.:

The first brace creates a new AnonymousInnerClass, the second declares an instance initializer block that is run when the anonymous inner class is instantiated.